1. DIURNAL VARIATIONS OF SULPHATE CONCENTRATION AND SULPHUR ISOTOPIC COMPOSITION (δ34S) OF SULPHATE ION IN THE SULEJOW RESERVOIR. Authors: W. DRZEWICKI, A. TROJANOWSKA, MARIUSZ-ORION JĘDRYSEK, D. LEWICKA-SZCZEBAK, MACIEJ GÓRKA, STANISLAW HAŁAS.2. ISOTOPIC COMPOSITION OF PRECIPITATION SULPHATES AS AN INDICATOR OF POLLUTANT ORIGIN IN WROCłAW (SW POLAND) PRECIPITATIONS. Authors: MACIEJ GÓRKA, MARIUSZ-ORION JĘDRYSEK, DARIUSZ STRĄPOĆ.3. DIURNAL VARIATIONS IN THE PHOTOSYNTHETIC ACTIVITY OF CYANOBACTERIAL BLOOM ON A FRESHWATER DAM RESERVOIR: AN ISOTOPIC STUDY. Authors: MARIUSZ-ORION JĘDRYSEK, L.I. WASSENAAR, A. TROJANOWSKA, D. LEWICKA-SZCZEBAK, M. KURASIEWICZ, W. DRZEWICKI.4. PARTITION OF SULFUR AND OXYGEN ISOTOPES IN SULFATE FROM CRYSTALLINE AQUIFERS OF THE SUDETY MOUNTAINS (POLAND). Authors: PIOTR JEZIERSKI, ANNA SZYNKIEWICZ, MAGDALENA MODELSKA, MARIUSZ-ORION JĘDRYSEK.